We propose a longitudinal study from birth to 24 months of infants exposed to cocaine in utero. The study focuses both on the identifiable short- term, neonatal manifestations of cocaine exposure and on the long-term effects on the infant's state regulatory capacities, regulation of attention, and the development of language and symbolic play. The use of cocaine by pregnant women has increased rapidly in the last five years and more and more fetuses are being exposed in utero. Many reports now document the neurophysiological manifestations of cocaine exposure in the immediate neonatal period, but there is little information about the neurobehavioral development of these infants after the first one to two months. The neuropharmacological effects of cocaine in animals and adults, as well as clinical reports describing attentional impairments exhibited by preschool children exposed to cocaine prenatally, suggest that infants exposed to cocaine in utero may be at continuing and serious risk for central nervous system dysfunction. In the proposed study, infants exposed to cocaine will be compared to infants whose mothers are drug-free. The project is being done in collaboration with an extensive treatment program for cocaine dependent pregnant women in which 300 women will be enrolled over a three year period. We will match the cocaine dependent group to the control group by maternal socioeconomic status, infant sex and birth order, and for a combination of infant birthweight and gestational age. Neonatal assessments of the infants will focus on the neurological organization as measured by the Brazelton Neonatal Behavior Assessment Scales (NBAS) and by the acoustic analysis of the infants' cries. After hospital discharge, infants will be seen at three, six, twelve, eighteen and twenty-four months for sequential assessments of the regulation of attentional states, the capacity to sustain exploration, state organization, adaptive behavior development, language and symbolic play development, and mental age. Additionally, because of the contributions of maternal behavior to the infant outcomes selected, we will examine both the mother's interactive style with her infant particularly in terms of attention directing activities and the intervening maternal variables likely to influence the mother's ability to respond to the infant (psychopathology, life stresses, anxiety and depression, and sense of parenting competence). We will also examine the influence of the substance abuse treatment program on the mothers' capacities to care for their infants. This study has important implications for understanding how the mother's use of cocaine during pregnancy may jeopardize the infant's developing attentional capacities through specific effects on fetal brain development. We expect that information from this longitudinal study will also be useful in designing service programs for such infants.